CN104703540B - X ray CT device, image processing apparatus and image processing method - Google Patents

Abstract

The X ray CT device of embodiment possesses collection portion, control unit and image reconstruction portion.Photon of the collection portion to origin in the X-ray for having passed through subject is counted, and the result that the energy to the photon counted is differentiated is collected as count results.Control unit notifies the energy set according to the X-ray absorption characteristic for the material specified by operator is split to gather above-mentioned collection portion.Image reconstruction portion receives above-mentioned collection portion by gathering splitting with above-mentioned energy multiple Energy identifying domains of setting distribution counting value and the count results that are collected into respectively, and carrys out reconstructed image data using the count results received.

Description

X ray CT device, image processing apparatus and image processing method

Technical field

Embodiments of the present invention are related to X ray CT device, image processing apparatus and image processing method.

Background technology

In recent years, developing using the detector of photon counting mode to carry out photon counting CT (Computed Tomography X ray CT device).The detector of integral form from being used in conventional X ray CT device is different, photon The signal that the detector output of counting mode can be counted respectively to origin in the photon for the X-ray for having passed through subject. Therefore, in photon counting CT, the high X ray CT image of SN ratios (Signal per Noise) can be rebuild.

In addition, the signal that the detector of photon counting mode is exported can be used in measuring each light that (discriminating) is counted The energy of son.Therefore, in photon counting CT, it will can be divided into by the data being collected into by a kind of tube voltage X-ray irradiation Multiple energy components carry out image conversion.For example, in photon counting CT, can generate can absorb the difference of limit to identify using K The image of material.As the material, contrast agent can be enumerated, being capable of distinguishingly chemical labeling material of tagged tissue etc..

So, in photon counting CT, differentiated by the way that each photon (photon) is divided into energy component, can Generation can identify the image of material of interest.But, if meticulously implementing Energy identifying, data volume becomes huge, The delivery time of data, reconstruction time increase.On the other hand, if roughly implementing Energy identifying, it can not obtain of interest Material identification needed for data.

Patent document 1：Japanese Unexamined Patent Publication 2012-34901 publications

The content of the invention

The problem to be solved in the present invention is that there is provided needed for a kind of image conversion for the material for being able to ensure that operator is of interest Data, and can cut down at X ray CT device, image processing apparatus and the image of data volume for carrying out image conversion Reason method.

The X ray CT device of embodiment possesses collection portion, control unit and image reconstruction portion.Collection portion to origin in The photon for having passed through the X-ray of subject is counted, the result that the energy to the photon of the counting is differentiated as Count results are collected.Control unit is notified according to the X-ray absorption characteristic for the material specified by operator above-mentioned collection portion The energy segmentation set (set) of setting.Image reconstruction portion receives above-mentioned collection portion respectively to according to above-mentioned energy segmentation set Multiple Energy identifying domain distribution counting values of setting and the count results that are collected into, figure is rebuild using the count results received As data.According to the MR imaging apparatus of above-mentioned composition, camera time can be shortened.

Brief description of the drawings

Fig. 1 is the figure for the configuration example for representing the X ray CT device involved by the 1st embodiment.

Fig. 2 is the figure for illustrating an example of the detector involved by the 1st embodiment.

Fig. 3 is for illustrating that K absorbs the figure of limit.

Fig. 4 A are for illustrating the figure of problem of the prior art (1).

Fig. 4 B are for illustrating the figure of problem of the prior art (2).

Fig. 5 A are the figures (1) of an example of the data structure for representing the data place storage shown in Fig. 1.

Fig. 5 B are the figures (2) of an example of the data structure for representing the data place storage shown in Fig. 1.

Fig. 6 is the figure for illustrating the control process that the control unit involved by the 1st embodiment is carried out according to the 1st setting method (1)。

Fig. 7 is the figure for illustrating the control process that the control unit involved by the 1st embodiment is carried out according to the 1st setting method (2)。

Fig. 8 is the figure for illustrating the control process that the control unit involved by the 1st embodiment is carried out according to the 1st setting method (3)。

Fig. 9 is for illustrating the control that the control unit involved by the 1st embodiment is carried out when multiple materials are designated The figure of processing.

Figure 10 is the figure (1) for an example for representing the 2nd setting method that the control unit involved by the 1st embodiment is carried out.

Figure 11 A are the figures (2) for an example for representing the 2nd setting method that the control unit involved by the 1st embodiment is carried out.

Figure 11 B are the figures (3) for an example for representing the 2nd setting method that the control unit involved by the 1st embodiment is carried out.

Figure 12 is the figure for an example for representing the 3rd setting method that the control unit involved by the 1st embodiment is carried out.

Figure 13 A are the figures (1) for an example for representing the GUI involved by the 1st embodiment.

Figure 13 B are the figures (2) for an example for representing the GUI involved by the 1st embodiment.

Figure 13 C are the figures (3) for an example for representing the GUI involved by the 1st embodiment.

Figure 13 D are the figures (4) for an example for representing the GUI involved by the 1st embodiment.

Figure 14 is the figure (5) for an example for representing the GUI involved by the 1st embodiment.

Figure 15 is the flow chart for illustrating an example of the processing of the X ray CT device involved by the 1st embodiment.

Figure 16 is the figure for the 1st configuration example for representing detector and collection portion shown in Fig. 1.

Figure 17 is the figure for the 2nd configuration example for representing detector and collection portion shown in Fig. 1.

Figure 18 is the figure for the 3rd configuration example for representing detector and collection portion shown in Fig. 1.

Embodiment

Hereinafter, referring to the drawings, the embodiment of X ray CT device is described in detail.

The X ray CT device illustrated in following embodiment is the device for being able to carry out photon counting CT.I.e., following The X ray CT device illustrated in embodiment is not the detector of conventional integral form (current-mode metering system), but logical Cross using the detector of photon counting mode to count the X-ray for having passed through subject, so as to rebuild SN than high X ray CT view data device.

In photon counting CT, counted and measured to measure light (X-ray) by the number to photon.The photon of unit interval Number is more, then as stronger light (X-ray).In addition, each photon has different energy, but in photon counting CT, lead to The energy measurement for carrying out photon is crossed, the information of the energy component of X-ray can be obtained.That is, in photon counting CT, it will can lead to The data being collected into a kind of tube voltage X-ray irradiation are crossed to be divided into multiple energy components to carry out image conversion.

Here, as the intrinsic energy component of material, thering is absorption to limit.Absorb limit (K absorb limit, L absorb limit) energy by Determined with absorbing the quantum number of shell electron and the electrical arrangement of valence band of atomic excitation.For example, in photon counting It is available to absorb the difference of limit to identify the view data of material using K in CT.

(the 1st embodiment)

First, the structure for the X ray CT device involved by the 1st embodiment is illustrated.Fig. 1 is to represent that the 1st is real Apply the figure of the configuration example of X ray CT device involved by mode.As shown in figure 1, the X ray CT dress involved by the 1st embodiment Put with frame device 10, bed apparatus 20 and control table apparatus 30.

Frame device 10 is to subject P X-ray irradiations, and to dress that the X-ray for having passed through subject P is counted Put, with high voltage generating unit 11, X-ray tube 12, detector 13, collection portion 14, swivel mount 15 and pallet drive division 16.

Swivel mount 15 is supported X-ray tube 12 and the opposed mode of detector 13 across subject P, by rear The circular frame that the pallet drive division 16 stated rotates at a high speed on the circuit orbit centered on subject P.

X-ray tube 12 is the high voltage that is supplied by high voltage generating unit 11 described later to subject P X-ray irradiation beams Vacuum tube, with the rotation of swivel mount 15, to subject P X-ray irradiation beams.

High voltage generating unit 11 is to supply high-tension device to X-ray tube 12, and X-ray tube 12 is used to be occurred by high voltage The high voltage that portion 11 is supplied produces X-ray.That is, high voltage generating unit 11 is by adjusting the tube voltage supplied to X-ray tube 12 Or tube current, to adjust the amount of x-ray irradiated to subject P.

Pallet drive division 16 penetrates X by rotation driving swivel mount 15 on the circuit orbit centered on subject P Spool 12 and detector 13 rotate.

Detector 13 has the multiple detections member for being used for being counted in the light for the X-ray for having passed through subject P to origin Part.Row are given one example, and each detecting element that the detector 13 involved by the 1st embodiment has is partly leading for cadmium telluride class Body.That is, the detector 13 involved by the 1st embodiment is that incident X-ray is directly changed into light, and to origin in X-ray The semiconductor detector of direct conversion hysteria that is counted of light.

Fig. 2 is the figure for illustrating an example of the detector involved by the 1st embodiment.For example, the 1st embodiment Involved detector 13 is as shown in Fig. 2 be the detecting element 131 that will be made up of cadmium telluride in the channel direction (Y-axis in Fig. 1 Direction) it is configured with N row, the face detector of M row is configured with body axis direction (Z-direction in Fig. 1).When photon is incident, inspection Survey the electric signal that element 131 exports 1 pulse., can be to origin by differentiating each pulse that detecting element 131 is exported Counted in the number of the photon (x-ray photon) for the X-ray for being incident to detecting element 131.In addition, by carrying out being based on each The calculation process of the intensity of pulse, can measure the energy of counted photon.

In addition, be that the situation of the semiconductor detector of direct conversion hysteria is illustrated below for detector 13, but the 1st real Apply the detector of indirect conversion type that mode for example can also apply to be made up of scintillator and photomultiplier and be used as detection Device 13 is come situation about using.

Collection portion 14 collects the count results of the result of the counting processing as the output signal for having used detector 13.Receive Collect photon (x-ray photon) of the portion 14 to origin in the X-ray that subject P is irradiated and passed through from X-ray tube 12 to count, The result that the energy of the photon counted will be identified is collected as count results.Moreover, collection portion 14 is by count results Sent to control table apparatus 30.

Specifically, collection portion 14 will differentiate each pulse exported of detecting element 131 and the x-ray photon that has counted The energy value of incoming position (test position) and the x-ray photon is as count results, by each phase (pipe of X-ray tube 12 Ball phase) it is collected.Collection portion 14 will for example output count used in pulse detecting element 131 position as entering Penetrate position.In addition, collection portion 14 for example according to the intrinsic receptance function of the peak value and system of pulse come computational power value.Or, Collection portion 14 is for example integrated come computational power value by the intensity to pulse.Collection portion 14 is by the energy value calculated (E) Distribute to multiple Energy identifying domains.

Collection portion 14 involved by present embodiment is distributed the energy value calculated for example using comparator (comparator) To multiple Energy identifying domains.Multiple Energy identifying domains turn into collection portion 14 in order to which the value to energy is differentiated and is assigned as regulation Granularity energy range, and use threshold value set energy segmentation set.

For example, the count results collected by collection portion 14 turn into " in pipe ball phase " in α 1 ", in incoming position " P11 " In detecting element 131, " count value of E1 ＜ E≤E2 " photon is " N1 ", Energy identifying domain " E2 ＜ E≤E3 " in Energy identifying domain Photon count value be " N2 " " etc. information.Or, the count results collected by collection portion 14 turn into " pipe ball phase " α 1 " In, in the detecting element 131 of incoming position " P11 ", " counting of the unit interval of E1 ＜ E≤E2 " photon of Energy identifying domain It is worth for " n1 ", the information such as Energy identifying domain " count value of the unit interval of E2 ＜ E≤E3 " photon is " n2 " ".

Bed apparatus 20 is the device for loading subject P, with top plate 22 and bed drive device 21.Top plate 22 is that mounting is tested Body P plate, bed drive device 21 moves top plate 22 to Z-direction, subject P is moved in swivel mount 15.

Wherein, frame device 10, which is for example performed, moves top plate 22 while making the rotation of swivel mount 15 come spirally right The helical scanning that subject P is scanned.Or, frame device 10 is performed subject P position after top plate 22 is moved Put the conventional sweep for immobilizing and making the rotation of swivel mount 15 be scanned with circular orbit to subject P.Or, frame device 10 perform the static intensity modulating side for making the position of top plate 22 move the progress conventional sweep in multiple scanning areas at certain intervals Formula.

It is to accept the operation that operator is carried out to X ray CT device to control table apparatus 30, and using by frame device 10 The count results being collected into rebuild the device of X ray CT view data.As shown in figure 1, there is control table apparatus 30 input to fill 31, display device 32, scan control section 33, pre-treatment portion 34, data for projection storage part 35, image reconstruction portion 36, image is put to deposit Storage portion 37, control unit 38, database 39.

Input unit 31 have operator's input of X ray CT device it is various indicate, mouse used in various settings or Keyboard etc., the information of the instruction accepted from operator, setting is transferred to control unit 38.For example, input unit 31 is from operation Person receive rebuild X ray CT view data when reconstruction condition, for image capture conditions of X ray CT view data etc..

Display device 32 is the display that operator carries out reference, under the control of control unit 38, shows that X is penetrated to operator Line CT view data, or show the GUI for accepting various instructions, various settings etc. from operator via input unit 31 (Graphical User Interface).For the GUI shown in the 1st embodiment, it will be described afterwards.

Scan control section 33 under the control of control unit 38 described later, control high voltage generating unit 11, pallet drive division 16, The action of collection portion 14 and bed drive device 21, thus controls the collection processing of the count information in frame device 10.

The count results that 34 pairs of pre-treatment portion is sent from collection portion 14 carry out logarithmic transformation processing, offset correction, sensitive The correction process such as correction, beam hardening correction are spent, to generate data for projection.

Data for projection storage part 35 stores the data for projection generated by pre-treatment portion 34.That is, data for projection storage part 35 is deposited Store up the data for projection (count results) for rebuilding X ray CT view data.

Image reconstruction portion 36 for example carries out inverse projection processing by the data for projection stored to data for projection storage part 35, To rebuild X ray CT view data.Handle, for example, can be enumerated based on FBP (Fi l tered Back as inverse projection Project ion) method inverse projection processing.In addition, image reconstruction portion 36 can also be rebuild by convergence method etc. Processing.In addition, image reconstruction portion 36 generates view data by carrying out various image procossings to X ray CT view data.Figure As the view data that reconstruction portion 36 is generated by the X ray CT view data after reconstruction, by various image procossings is stored in image In storage part 37.

Here, in the data for projection that basis is generated by the count results that photon counting CT is obtained, comprising because passing through quilt Corpse or other object for laboratory examination and chemical testing P and the information of the energy of X-ray decayed.Therefore, image reconstruction portion 36 can for example rebuild the X of specific energy component Ray CT view data.In addition, image reconstruction portion 36 can for example rebuild the respective X ray CT picture number of multiple energy components According to.

In addition, image reconstruction portion 36 for example can to the distribution of each pixel of the X ray CT view data of each energy component with The corresponding tone of energy component, and generated overlapping and multiple X ray CT picture numbers after color are distinguished according to energy component According to view data.In addition, image reconstruction portion 36 can absorb limit using the intrinsic K of material, the material can be identified to generate View data.Other view data generated as image reconstruction portion 36, can enumerate homogeneous X-ray view data, density View data or actual effect atom numbering view data etc..

Database 39 is the storage part of the storage information related to the respective X-ray absorption frequency spectrum of multiple materials.That is, data Storehouse 39 is the database for storing analytical chemistry information.Database 39 can use the information in the analytical chemistry data storehouse of outside, come Update and keep the various information of analytical chemistry.

Control unit 38 is by controlling frame device 10, bed apparatus 20 and the action for controlling table apparatus 30, to carry out X-ray The overall control of CT devices.Specifically, control unit 38 is by controlling scan control section 33, to control to be carried out by frame device 10 CT scan.In addition, control unit 38 is by controlling pre-treatment portion 34, image reconstruction portion 36, to control in table apparatus 30 Image reconstruction process, image generation processing.In addition, control unit 38 is controlled, so as to by image storage part 37 stored it is each Plant view data and be shown in display device 32.Wherein, the control process carried out in the 1st embodiment for control unit 38, it After will be described.

More than, the overall structure for the X ray CT device involved by the 1st embodiment is illustrated.In the structure Under, the X ray CT device involved by the 1st embodiment is by photon counting CT, to carry out the energy point that make use of material intrinsic Reconstruction processing, the generation processing of the view data of amount.

Here, absorbing limit for the K of an example as the intrinsic energy component of material, illustrated using Fig. 3. Fig. 3 is for illustrating that K absorbs the figure of limit.In fig. 3 it is shown that the X-ray absorption frequency spectrum of various materials.Wherein, Fig. 3 transverse axis It is energy (unit：KeV), Fig. 3 longitudinal axis is line attenuation coefficient (unit：cm^-1)。

In figure 3 it is shown that being mixed with the X-ray absorption frequency of the blood (Iodine-mixed blood) of the contrast agent of iodine class Compose, be mixed with the X-ray absorption frequency spectrum of the blood (Gd-mixed blood) of the contrast agent of gadolinium class, be mixed with the contrast agent of bismuth class Blood (Bi-mixed blood) X-ray absorption frequency spectrum.In addition, in figure 3, also matchingly show water (Water), under The X-ray absorption frequency spectrum of limb (Rib), vertebra (Spi).

Like that, before and after K absorbs limit, attenuation coefficient coefficient steeply rises example as shown in Figure 3.If for example, K absorbed The iodine of " 33.16keV " is limited to as concern material, then has passed through the meter of the x-ray photon of the tissue for the contrast agent that there is iodine class Numerical value differs widely in the energy range before and after " 33.16keV ".In consideration of it, identifying material when absorbing the difference of limit using K When, the count results (data for projection) that image reconstruction portion 36 is for example less than the Energy identifying domain that K absorbs limit according to value are penetrated to rebuild X Line CT view data (hereinafter referred to as the 1st view data).In addition, image reconstruction portion 36 is for example more than the energy that K absorbs limit according to value Amount differentiates the count results (data for projection) in domain to rebuild X ray CT view data (hereinafter referred to as the 2nd view data).Moreover, Image reconstruction portion 36 from the 2nd view data for example by subtracting the 1st view data, to generate difference image data.In the difference In view data, the region (for example, there is the tissue of the contrast agent of iodine class) that count value differs widely mainly is depicted.

But, when meticulously implementing Energy identifying, data volume becomes huge, and the transfer time of data, reconstruction time increase Greatly.On the other hand, when roughly implementing Energy identifying, it is impossible to obtain the data needed for the identification of material of interest.Pin To the point, illustrated using Fig. 4 A and Fig. 4 B.Fig. 4 A and Fig. 4 B are the figures for illustrating problem of the prior art.In figure In 4A, example goes out with the Energy identifying domain of thick granularity setting, and in figure 4b, example goes out with the Energy identifying of thin granularity setting Domain.In addition, in Fig. 4 A and Fig. 4 B, example goes out the X-ray absorption of different two kinds of materials (substance A and substance B) respectively Frequency spectrum.

When example as shown in Figure 4 A like that, when setting 5 Energy identifying domain (0~4) with the thick granularity of same widths, energy Enough reduce the data volume produced as count results.But, because 5 respective energy ranges in Energy identifying domain are wider, because This, according to the low view data of distinguishing ability of the view data as material of the count results in each Energy identifying domain generation.Example Such as, the Energy identifying domain (0) and Energy identifying domain (1) shown in Fig. 4 A are drawn using the K of the substance A energy values for absorbing limit as border Point.Therefore, it is possible to using the count results of the count results of Energy identifying domain (0) and Energy identifying domain (1), be reflected to generate Determine the difference image data of substance A.On the other hand, for example in the immediate vicinity inclusion in the Energy identifying domain (1) shown in Fig. 4 A Matter B K absorbs the energy value of limit.Even if thus, for example count results and Energy identifying domain (2) using Energy identifying domain (1) Count results generate difference image data, the difference image data is nor the difference image data of substance B can be identified.

In contrast, when example as shown in Figure 4 B like that, 15 Energy identifying domains are set with the thin granularity of same widths When (0~14), because 15 respective energy ranges in Energy identifying domain are narrow, therefore, according to the counting knot in each Energy identifying domain The high view data of distinguishing ability of the view data that fruit generates as material.For example, the energy exemplified by Fig. 4 B can be used Differentiate the count results of domain (2) and the count results of Energy identifying domain (3), to generate the difference image number that can identify substance A According to.In addition, can for example use the count results in the Energy identifying domain (5) exemplified by Fig. 4 B and the counting of Energy identifying domain (6) As a result, the difference image data of substance A can be differentiated to generate.But, when example like that, is set with thin granularity as shown in Figure 4 B During multiple Energy identifying domains, the data volume increase produced as count results.

So, if roughly setting Energy identifying domain for carrying out the data volume of image conversion in the past in order to reduce, have When cannot ensure data needed for the image conversion of operator's material of interest.If in addition, in the past in order to ensure operator is closed Data needed for the image conversion of the material of note and more carefully set Energy identifying domain, then for carrying out the data quantitative change of image conversion It is many.

In consideration of it, control unit 38 involved by the 1st embodiment is in order to ensure the image of operator's material of interest On the basis of data needed for changing, cut down for carrying out the data volume of image conversion, and following control is carried out to collection portion 14.

That is, control unit 38 is directed to collection portion 14, and energy is set according to the X-ray absorption characteristic for the material specified by operator Amount segmentation set.Moreover, control unit 38 notifies set energy segmentation set to collection portion 14.Here, control unit 38 exists Collect setting energy segmentation set before count results.

By the control, collection portion 14 by by energy split gather setting multiple Energy identifying domains distribute respectively in terms of Numerical value, to collect count results and be sent to frame device 30.Moreover, image reconstruction portion 36 uses what is received from collection portion 14 Count results carry out reconstructed image data.Image reconstruction portion 36 is generated using basis from the count results that collection portion 14 is received Data for projection carrys out reconstructed image data.

I.e., in the present embodiment, control unit 38 is according to the X-ray absorption characteristic of operator's material of interest, actively Ground setting energy segmentation set.In other words, needed for control unit 38 sets the image conversion as ensuring operator's material of interest The energy segmentation set that multiple Energy identifying domains composition of information and the quantity in Energy identifying domain tail off.

Here, the X-ray absorption characteristic for the material specified by operator, which is, for example, K, absorbs the intrinsic characteristic energy of material such as limit Value.K, which absorbs the characteristic energies values such as limit, to be inputted by operator, but in order to carry out the operation, operator needs to investigate itself The characteristic energies value of material of interest.Present embodiment can also input the intrinsic characteristic energies value of material by operator Situation, but in order to mitigate the burden of operator, above-mentioned database 39 is set.That is, control unit 38 uses storage and multiple materials The database 39 of the related information of respective X-ray absorption frequency spectrum, splits set to set above-mentioned energy.

Here, when the material specified by operator is one, the control unit 38 involved by the 1st embodiment is according to the 1st Setting method splits the setting gathered to carry out energy.In addition, when the material specified by operator is multiple, the 1st embodiment The 3rd setting method that involved control unit 38 is combined with according to the 2nd setting method or by the 1st setting method and the 2nd setting method come pair Energy segmentation set is set.

First, the control process carried out for control unit 38 according to the 1st setting method, uses Fig. 5 A, Fig. 5 B, Fig. 6 and Fig. 7 To illustrate.Fig. 5 A and Fig. 5 B are the figure of an example of the data structure for representing the database purchase shown in Fig. 1, Fig. 6 And Fig. 7 is the figure for illustrating the control process that the control unit involved by the 1st embodiment is carried out according to the 1st setting method.Its In, control explained below processing is to be applied to generation to absorb the difference of limit to identify the difference image of material using K The processing of data.

First, accepted when from operator to during the input for the parameter that can determine material, control unit 38 takes from database 39 Obtain the intrinsic characteristic energies value of the material being consistent with the parameter accepted.That is, control unit 38 carries out thing using database 39 The retrieval process of the intrinsic energy component of matter.

For example, database 39 is as shown in Figure 5A, will " material name：A " and " trade name：A ' " and " X-ray absorption frequency spectrum：S (A) correspondence " is set up to store.Database 39 exemplified by Fig. 5 A turns into the respective X-ray absorption frequency spectrum of multiple materials with making The material name of parameter to can determine material establishes the data configuration of association with trade name.

Or, database 39 as shown in Figure 5 B, will " material name：A ", " trade name：A ' ", " K absorption limits：E_K(A) " and " L absorbs limit：E_L(A) correspondence " is set up to store.Database 39 exemplified by Fig. 5 B turns into each X-ray of multiple materials The characteristic energies value of absorption spectrum addition feature establishes pass with the material name as the parameter that can determine material and trade name The data configuration of connection.

So, database 39 and the title (material name or trade name) including contrast agent and the material of chemical labeling material Set up at least one of the X-ray absorption coefficient for accordingly storing the material being consistent and characteristic energies value.

In addition, in the 1st embodiment, (control table apparatus 30 is arranged in X ray CT device for database 39 It is interior) situation illustrate, but the 1st embodiment can also be database 39 be arranged at X ray CT device (control table apparatus 30) situation of outside.Now, control table apparatus 30 and database 39 are connected by wire net or wireless communication networks.

Fig. 6 illustrates an example of control process when carrying out 1 setting method by sequence chart.As shown in fig. 6, control Portion 38 sends the parameter that operator is inputted, and database 39 is inquired about.For example, control unit 38 inquires about " thing to database 39 Matter name：AAA, characteristic energies：K absorbs limit ".Here, setting " material name：AAA " is the contrast agent name of xenon class.Database 39 is by " thing Matter name：AAA, characteristic energies：K absorbs limit " as search key, to retrieve the data itself stored, retrieval result is returned Answer to control unit 38.For example, as shown in fig. 6, due to " material name：AAA " is the contrast agent name of xenon class, and therefore, database 39 will The K of xenon absorbs limit " E_K=34.56keV " is answered to control unit 38.Wherein, when database 39 is arranged at outside the present apparatus, control Portion 38 processed is inquired about the database 39 for being arranged at the outside of the present apparatus via communication network.

In the above cases, database 39 has search function.That is, control unit 38 requires that retrieval is inputted with operator Parameter as the characteristic energies value of keyword, the parameter that database 39 retrieves the inquiry using control unit 38 is additional to is used as key The characteristic energies value of word, and answer retrieval result.Wherein, when the result of retrieval is that data corresponding with parameter are not present, number According to the information such as answering " not finding " of storehouse 39.

But, the 1st embodiment can also be retrieved by control unit 38.Now, control unit 38 inputs operator Parameter is retrieved as keyword in database 39, to obtain the characteristic energies value that material corresponding with parameter is intrinsic (for example, K absorbs limit).

In addition, above-mentioned be directed to together with material name regard the species of energy component as the parameter of retrieval and situation about using It is illustrated, but the 1st embodiment can also use material name, trade name as the parameter of retrieval, without by spy The species of performance amount is used as the parameter of retrieval.Now, database 39 answers multifrequency nature energy value to control unit 38, display device 32 for example shows the table for the multiple characteristic energies values for designating species according to the control of control unit 38.Operator After it have references to table, characteristic energies value used in designated substance identification is carried out using input unit 31 etc..

By above-mentioned processing, when the characteristic energies for obtaining the X-ray absorption characteristic for representing the material specified by operator During value, as the 1st setting method, as shown in fig. 6, control unit 38 is centered on characteristic energies value, to set different multiple of granularity Energy identifying domain.Specifically, control unit 38 sets energy to the energy area of the vicinity of characteristic energies value with tiny granularity Differentiate domain.In addition, control unit 38 is set to the energy area beyond the energy area of the vicinity of characteristic energies value with thick granularity Energy identifying domain.

Split an example of set for the energy set by the 1st setting method, illustrated using Fig. 7.Fig. 7 is represented When generation has used the K of xenon to absorb limit " E_KDuring=34.56keV " difference image data, the energy set by the 1st setting method Split an example of set.Wherein, the longitudinal axis of the X-ray absorption frequency spectrum shown in Fig. 7 is mass attentuation coefficient.

Exemplified by Fig. 7 " 0~9 " are denoted as 10 energy mirror of energy segmentation set for being set by control unit 38 respectively Other domain " ER0~ER9 ".Like that, control unit 38 is absorbing limit " E to example as shown in Figure 7 with the K of xenon_KCentered on=34.56keV " In neighbouring energy area, " ER4, ER5, ER6, the ER7 " of narrow width are set.In the case of exemplified by Fig. 7, ER5 and ER6 Border and xenon K absorb limit " E_K=34.56keV " correspondences.

Moreover, example is such as shown in Figure 7, control unit 38 is for " region beyond ER4~ER7 " region, setting ratio " " ER0, ER1, ER2, ER3 " and " ER8, the ER9 " of the wide width of ER4~ER7 " width.In the case of exemplified by Fig. 7, mirror The width in other domain is " ER0=ER1=ER2=ER9 ＞ ER3=ER8 ＞ ER4=ER5=ER6=ER7 ".

The X-ray absorption frequency spectrum for paying close attention to the material beyond material is smooth in the near zone that the K of concern material absorbs limit Ground changes.In order to effectively remove the information of the material beyond xenon by difference processing, energy preferably used in constriction difference Scope.Therefore, control unit 38 is directed to the area of the information needed for the generation of the difference image data comprising the K absorption limits for having used xenon Domain, is adjusted in the way of the K that ER5 and ER6 border turns into xenon absorbs limit, set narrow width " ER4, ER5, ER6、ER7”。

In addition, the K that the generation that the difference image data of limit is absorbed using K is not necessarily required to pay close attention to material absorbs the attached of limit Region beyond near field.Therefore, control unit 38 absorbs the " area beyond ER4~ER7 " of the near zone of limit in the K as xenon In domain, the Energy identifying domain of wide width is set.

Moreover, control unit 38 by the related setting value of set is split to set energy as shown in fig. 6, notify to collection Portion 14.The setting value, which turns into, to be used to the count results for each pulse for calculating energy value distributing to 10 Energy identifying domain " ER0 ~ER9 " multiple threshold values.When starting CT scan after setting energy segmentation set, as shown in fig. 6,14 pairs of collection portion Each Energy identifying domain distribution counting value.

In fig. 8, the result for arranging and being differentiated to the pulse exported by detector 13 along time series is illustrated Obtained from each x-ray photon energy value bar chart.In the case of exemplified by Fig. 8, collection portion 14 collects the meter of " ER0 " Numerical value " C (ER0) " is " 3 ", and the count value " C (ER1) " of " ER1 " is " 4 ", and the count value " C (ER2) " of " ER2 " is " 4 ", " ER3 " Count value " C (ER3) " be " 5 " count results.

In addition, in the case of exemplified by Fig. 8, the count value " C (ER4) " that collection portion 14 collects " ER4 " is " 1 ", " ER5 " Count value " C (ER5) " be " 2 ", the count value " C (ER6) " of " ER6 " is " 0 ", and the count value " C (ER7) " of " ER7 " is " 1 " Count results.In addition, in the case of exemplified by Fig. 8, the count value " C (ER8) " that collection portion 14 collects " ER8 " is " 0 ", The count value " C (ER9) " of " ER9 " is the count results of " 1 ".

Collection portion 14 is collected " C (ER0)~C (ER9) " with each pipe ball phase, and is sent to control table apparatus 30.Then, scheme As reconstruction portion 36 carries out image reconstruction process.For example, as shown in fig. 7, image reconstruction portion 36 according to control unit 38 instruction, or According to the instruction of operator, the 1st picture number is rebuild according to data for projection corresponding with the count results of " C (ER4)+C (ER5) " According to 101.In addition, for example, as shown in fig. 7, image reconstruction portion 36 according to control unit 38 instruction, or according to the finger of operator Show, the 2nd view data 102 is rebuild according to data for projection corresponding with the count results of " C (ER6)+C (ER7) ".Moreover, example Such as, as shown in fig. 7, image reconstruction portion 36 from the 2nd view data 102 by subtracting the 1st view data 101, to generate difference diagram As data 103.Display device 32 shows difference image data 103 according to the control of control unit 38.

In addition, image reconstruction portion 36 can also the control based on control unit 38, for example, as shown in fig. 7, generation make the 2nd figure As data 102 are overlapped in the overlapping image data 104 of difference image data 103.In difference image data 103, depict point It is furnished with the region of the contrast agent of xenon class.But, in order that operator confirms that the region is corresponding with which region, preferably display makes to retouch Draw the view data that the overall X ray CT view data of tissue morphology is overlapped in difference image data 103.Wherein, as weight The X ray CT view data of overlay elephant can be the 1st view data 101 or according to corresponding with whole count results Data for projection and the X ray CT view data rebuild.

In addition, the 1st view data 101 can also be according to projection number corresponding with the count results of " C (ER3)~C (ER5) " Rebuild according to or with the count results corresponding data for projection of " C (ER0)~C (ER5) ".Equally, the 2nd view data 102 also may be used By according to data for projection corresponding with the count results of " C (ER6)~C (ER8) " or according to in terms of " C (ER6)~C (ER9) " The corresponding data for projection of result is counted to rebuild.Condition change can be by with reference to difference image data 103, overlapping image data 104 operator arbitrarily changes.

Then, for the 2nd setting method and the 3rd setting method, entered using Fig. 9, Figure 10, Figure 11 A, Figure 11 B and Figure 12 Row explanation.Fig. 9 is for illustrating at the control that the control unit involved by the 1st embodiment is carried out when multiple materials are designated The figure of reason.In addition, Figure 10, Figure 11 A and Figure 11 B are to represent the 2nd setting method that the control unit involved by the 1st embodiment is carried out An example figure, Figure 12 is an example for representing the 3rd setting method that control unit involved by the 1st embodiment is carried out Figure.

Fig. 9 illustrates an example of control process when carrying out the 2nd setting method or 3 setting method by sequence chart. As shown in figure 9, control unit 38 sends the multiple parameters of operator's input, to carry out the inquiry of multiple materials to database 39.Example Such as, control unit 38 inquires about database 39 " material name：A, characteristic energies：K absorptions limit ", " material name：B, characteristic energies：K absorbs Limit " and " material name：C, characteristic energies：K absorbs limit ".Here, setting " material name：A " is the contrast agent name of iodine class, " material name： B " is the contrast agent name of gadolinium class, " material name：C " is the contrast agent name of bismuth class.

Database 39 will " material name：A, characteristic energies：K absorptions limit ", " material name：B, characteristic energies：K absorbs limit " and " material name：C, characteristic energies：K absorbs limit " as search key, to retrieve the data itself stored, and by retrieval result Answer to control unit 38.Database 39 is for " material name：A, characteristic energies：K absorbs limit ", the K of iodine is absorbed into limit " E_K= 33.16keV " is used as " threshold value：Th2 " is answered to control unit 38.In addition, database 39 is for " material name：B, characteristic energies：K Absorb limit ", the K of gadolinium is absorbed into limit " E_K=50.24keV " is used as " threshold value：Th3 " is answered to control unit 38.In addition, database 39 for " material name：B, characteristic energies：K absorbs limit ", the K of bismuth is absorbed into limit " E_K=90.55keVkeV " is used as " threshold value： Th4 " is answered to control unit 38.In addition, control unit 38 can be retrieved in database 39 obtaining " Th2, Th3, Th4 ", can also receive " Th2, Th3, Th4 " from operator.

Moreover, control unit 38 is as shown in figure 9, set the energy segmentation set of each material, by the energy for setting each material The setting value of amount segmentation set is notified to collection portion 14.Swept when starting CT after the energy for setting each material splits set When retouching, as shown in figure 9, each Energy identifying domain distribution counting value of each material of 14 pairs of collection portion.

When specifying multiple materials by operator, the control unit 38 for carrying out the 2nd setting method is penetrated according to the X for representing each material The characteristic energies value of line absorption characteristic sets multiple Energy identifying domains, and sets energy segmentation set.For example, such as Figure 10 institutes Show, with " Th2, Th3, together with Th4 ", control unit 38 use as the lower threshold for judging noise grade " Th1 " and use In judge rebuild processing unwanted energy grade upper limit threshold " Th5 ", to set multiple Energy identifying domains.Here, " Th1 " and " Th5 " is the threshold value that system is inherently set, and is the value set in advance in control unit 38.That is, control unit 38 is used " Th2, Th3, Th4 ", the intrinsic lower threshold of system is used as what appointed 3 materials distinguished intrinsic threshold value " Th1 " and " Th5 " as the intrinsic upper limit threshold of system, to set 4 Energy identifyings for distribution counting result Domain.

For example, control unit 38 sets the " ER (1) represented in Fig. 10 by " 1 "：Th1≤E ＜ Th2 ", in Fig. 10 by " 2 " " the ER (2) represented：Th2≤E ＜ Th3 ", " ER (3) represented in Fig. 10 by " 3 "：Th3≤E ＜ Th4 ", in Fig. 10 by " the ER (4) that " 4 " are represented：Th4≤E ＜ Th4 ".Wherein, control unit 38 is set as the " ER (0) that will be represented in Fig. 10 by " 0 "：E ＜ Th1 " count results are discarded.In addition, control unit 38 is set as " ER (5) (not shown) in Fig. 10：Th5 ＜ E " meter Number result is discarded.

Moreover, control unit 38 is also by the way that according to the respective characteristic energies value of multiple materials, multiple Energy identifying domains are bound For multiple Energy identifying domains of thick granularity, thus gather to set the respective energy segmentation of multiple materials.For example, such as Figure 10 institutes Show, control unit 38 is according to " " ER (1) " and " ER (2)+ER (3)+ER (4) " this 2 is set as I (iodine) by Th1, Th2, Th5 " Energy segmentation set.In addition, for example, as shown in Figure 10, control unit 38 is according to " Th1, Th3, Th5 " are by " ER (1)+ER " and " ER (3)+ER (4) " this 2 energy segmentation set for being set as Gd (gadolinium) (2).In addition, for example, as shown in Figure 10, Control unit 38 is according to " " ER (1)+ER (2)+ER (3) " and " ER (4) " this 2 is set as that Bi (bismuth) is used by Th1, Th4, Th5 " Energy segmentation set.

Here, the count value of " ER (1) " is set as " C (ER1) ", if the count value of " ER (2) " is " C (ER2) ", if " ER (3) count value " is " C (ER3) ", if the count value of " ER (4) " is " C (ER4) ".

When setting the segmentation set of the energy shown in Figure 10, as shown in Figure 11 A, I count results, collection portion are used as 14 send " C (ER1) " and additive value " C (ER2)+C (ER3)+C (ER4) " to control table apparatus 30.In addition, such as Figure 11 A institutes Show, as Gd count results, collection portion 14 will add up value " C (ER1)+C (ER2) " and additive value " C (ER3)+C (ER4) " Sent to control table apparatus 30.In addition, as shown in Figure 11 A, as Bi count results, collection portion 14 will add up value " C (ER1)+C (ER2)+C (ER3) " and " C (ER4) " are sent to control table apparatus 30.

Thus, as shown in Figure 11 A, image reconstruction portion 36 generates difference image data (I), root according to I count results According to Gd count results generation difference image data (Gd), difference image data (Bi) is generated according to Bi count results.

In addition, the 1st embodiment for example can also be by control unit 38 by the energy of " ER (1), ER (2), ER (3), ER (4) " Segmentation set is notified to collection portion 14.Now, collection portion 14 is sent " C (ER1), C (ER2), C (ER3), C (ER4) ".Moreover, root According to the instruction of control unit 38, image reconstruction portion 36 splits the data for projection of " C (ER1), C (ER2), C (ER3), C (ER4) " to I Data for projection, Gd data for projection, Bi data for projection, to generate difference image data (I), difference image data And difference image data (Bi) (Gd).

In the case of any one, ensure to have used the distinguishing ability of the difference image data of each material, and data volume Reduce.In addition, for example condition change can also be carried out by the operator with reference to each difference image data, so as to only in each material K, which is absorbed in the Energy identifying domain before and after limiting, carries out difference processing.Now, as shown in Figure 11 B, as I count results, collect Portion 14 sends " C (ER1) " and " C (ER2) " to control table apparatus 30.In addition, as shown in Figure 11 B, being used as Gd counting knot Really, collection portion 14 sends " C (ER2) " and " C (ER3) " to control table apparatus 30.In addition, as shown in Figure 11 B, being used as Bi's Count results, collection portion 14 sends " C (ER3) " and " C (ER4) " to control table apparatus 30.

But, in the case of exemplified by Figure 11 B, exist and reduced for the information content of image conversion and used difference image The possibility of the distinguishing ability reduction of data.Therefore, if carry out the processing exemplified by Figure 11 B and for example selected by operator. In order to ensure having used the distinguishing ability of difference image data, it is desirable to carry out the processing exemplified by Figure 11 A.

Then, illustrated for the 3rd setting method.When specifying multiple materials by operator, the 3rd setting method is carried out Control unit 38 obtains the characteristic energies value (Th2, Th3, Th4) of each material, and the energy of each material is set by the 1st setting method Segmentation set.Wherein, together with the characteristic energies value of each material, control unit 38 also uses above-mentioned Th1 and Th5.For example, such as Shown in Figure 12, control unit 38 sets the Energy identifying domain of thin granularity for the region centered on Th2 value (in reference picture " 1 " and " 2 "), for the region beyond the region set thick granularity Energy identifying domain (" 3 " in reference picture and " 4 "), so as to set I energy segmentation set.

In addition, as shown in figure 12, control unit 38 sets the energy mirror of thin granularity for the region centered on Th3 value Other domain (" 2 " and " 3 " in reference picture), the Energy identifying domain (reference of thick granularity is set for the region beyond the region " 1 ", " 4 " and " 5 " in figure), so as to set Gd energy segmentation set.In addition, as shown in figure 12, the pin of control unit 38 The Energy identifying domain (" 3 " and " 4 " in reference picture) of thin granularity is set to the region centered on Th4 value, for this Region beyond region sets the Energy identifying domain (" 1 ", " 2 " and " 5 " in reference picture) of thick granularity, so as to set Bi use Energy segmentation set.Moreover, control unit 38 notifies the energy segmentation set of each material shown in Figure 12 to collection portion 14, To start CT scan.

Wherein, in the 3rd setting method shown in Figure 12, except 5 threshold values, " in addition to Th1~Th5 ", collection portion 14 is also needed to Energy identifying is carried out using 7 threshold values.In consideration of it, control unit 38 can also be adjusted, so as in accordance with the 1st setting method The Energy identifying domain of each material of setting in the scope of rule, except 5 threshold values are " in addition to Th1~Th5 ", used in collection portion 14 Threshold value tails off.

Control unit 38 involved by 1st embodiment is also made the setting that the energy notified to collection portion 14 splits set Setting value (multiple threshold values) is corresponding with the material foundation being consistent to be stored in defined storage part.It is used as the defined storage Portion, being capable of enumerated data storehouse 39.For example, as shown in fig. 6, the control unit 38 for having carried out the 1st setting method requires database 39 to protect Pipe setting value.Thus, such as database 39 and " material name：AAA " etc. sets up accordingly storage, and " ER0~ER9 " setting is made Setting value.By the processing, when being accepted again from operator to " material name：AAA " it is specified when, database 39 for control The inquiry in portion 38 processed, answers " ER0~ER9 " setting value.In addition, as defined storage part, control unit 38 can also be used Internal storage in the present apparatus.

In addition, the control unit 38 for for example having carried out the 2nd setting method or the 3rd setting method is required database 39 as shown in Figure 9 The setting value of each material of keeping.Thus, such as database 39 and " material name：I " etc. set up accordingly storage " ER (1) " and The setting value of " ER (2)+ER (3)+ER (4) ".In addition, such as database 39 and " material name：Gd " etc., which is set up, accordingly stores " ER (1)+ER (2) " and the setting value of " ER (3)+ER (4) ".In addition, such as database 39 and " material name：Bi " etc. sets up correspondence The setting value of ground storage " ER (1)+ER (2)+ER (3) " and " ER (4) ".

Pass through the setting for the energy segmentation set for carrying out the setting method of the 1st setting method~the 3rd more than having used, collection portion 14 Collect the count results that ensure that the information needed for the image conversion of operator's material of interest.The data volume of the count results is led to The setting of energy segmentation set is crossed, such as compared with the energy segmentation set shown in Fig. 4 B, is greatly reduced

Then, shown for control unit 38 for carrying out above-mentioned processing, operator in order to carry out input operation GUI, is illustrated using Figure 13 A, Figure 13 B, Figure 13 C, Figure 13 D and Figure 14.Figure 13 A, Figure 13 B, Figure 13 C, Figure 13 D and Figure 14 is the figure for an example for representing the GUI involved by the 1st embodiment.

For example, passing through the control of control unit 38, the as shown in FIG. 13A, " data display area 200 " with display image data Together, display device 32 shows the input GUI300 that the parameter that can determine material is inputted for operator.

In the frame 301 in GUI300, being configured with for operator's input parameter of the input exemplified by Figure 13 A.Operator Using mouse come choice box 301, for example, as shown in Figure 13 B, parameter " AAA " is inputted to frame 301 using keyboard.Moreover, operation Person presses the shortcut of retrieval request after inputted parameter is confirmed, such as.Thus, Fig. 6 is automatically begun to use Retrieval process or control process that~Fig. 8 is illustrated.

In addition, operator using mouse come choice box 301, for example, as shown in fig. 13 c, using keyboard by parameter " I, Gd, Bi " is input in frame 301.Moreover, operator presses the quick of retrieval request for example after inputted parameter is confirmed Key.Thus, the retrieval process or control process that Fig. 9~Figure 11 B are illustrated automatically are begun to use.

Also, by the control of control unit 38, display device 32 will be notified for read-out control part 38 to collection portion 14 The operation button of setting value is shown in display device 32.Control unit 38 will set the energy segmentation set that notifies to collection portion 14 and The setting value (multiple threshold values) used is set up with the material being consistent and is accordingly stored in database 39 or internal storage.In view of This, in the processing on GUI 300, being configured with for performing the setting value for having used temporary transient setting of the input exemplified by Figure 13 A Quick operation button group 302 (operation button 302a~302d).

For example, example is such as illustrated in figure 13d, operation button 302a is to be used for control unit 38 from database 39 or storage inside Device is obtained to be controlled in the setting of the energy segmentation set of I energy segmentation set, Gd energy segmentation set and Bi The operation button of setting value used in portion 38 processed.For example, as illustrated in figure 13d, operator move the cursor to and record " I, On the operation button 302a of Gd, Bi " word, clicked using mouse.Thereby, it is possible to start to be used for collect " I, Gd, Bi " The CT scan of respective difference image data.

In the above cases, each quick botton shown as operation button group 302 has used frame as operator The history information of 301 operation, automatically generates and is shown in input GUI300.That is, in order to pair in practice to point The chemical substance with actual effect analysed and used carries out the image conversion for identification, can be without using the ground of frame 301 with doctor The mode reassigned, generates and shows operation button group 302 fast.Wherein, the energy set by the 1st~the 3rd setting method As long as amount segmentation set is set before CT scan.Therefore, present embodiment can also be operation button group 302 fast It is set to the situation of chemical substance that may be frequently used to analyze.

For for the chemical substance analyzed with and may frequently used, such as by prior doctor or attendant Input operation, control unit 38 is set energy segmentation set in advance, by the keeping of thus obtained setting value in database 39 or In internal storage.Thus, the chemical substance that control unit 38 generates and shown to analyze with and may frequently use it is quick Button.In addition, in order to which the quick botton for the chemical substance analyzed with and may frequently used can not also obtain setting value in advance, And the single-click operation to be carried out for quick botton is used for control unit 38 and the thing being consistent is inquired about in database 39 as opportunity The characteristic energies value of matter.

In addition, as using Fig. 7 explanations, when having carried out 1 setting method, sometimes according to the specified of operator, according to The count results of " C (ER4)+C (ER5) " rebuild the 1st view data 101, according to the count results of " C (ER6)+C (ER7) " come Rebuild the 2nd view data 102.Now, " ER4+ is turned into order to carry out the data needed for the corresponding image conversion of requirement with operator ER5 " and " ER6+ER7 " the two Energy identifying domains.In addition, the 2nd setting method as having carried out shown in Figure 11 B In the case of, the energy segmentation set of each material is also changed.

Further, since the reason such as physical characteristic of detector 13 or collection portion 14, the value of the energy measured sometimes with it is true Positive energy value is inconsistent, for example, threshold value (for example, K absorbs the value of limit) sometimes set by control unit 38 is not optimal sets Definite value.Now, the setting value set by operator's change control unit 38.

So, in the present embodiment, the condition (energy that control unit 38 sets for image conversion is changed by operator sometimes Amount segmentation set).When the material that condition change had been carried out to the past carries out image conversion, again by manual change control unit 38 The condition set automatically for image conversion is burden for operator.In consideration of it, when the bar carried out according to operator When part changes energy segmentation set, control unit 38 splits energy setting value and phase used in the reset of set The material of symbol is set up and is accordingly stored in database 39 or internal storage.Moreover, control unit 38 is used in reading energy point The operation button of setting value is shown in display device 32 used in the reset that cut set is closed.

For example, in the case where having carried out the change of the condition shown in Figure 11 B, control unit 38 preserves setting I energy point Cut set closes the setting value of " ER (1), ER (2) ", the setting value of setting Gd energy segmentation set " ER (2), ER (3) ", setting The setting value of Bi energy segmentation set " ER (3), ER (4) ".Moreover, as reading based on the condition shown in Figure 11 B The quick botton of the setting value of change, as shown in figure 14, control unit 38 show " operation button 302a ' ".In " operation button On 302a ' ", for example, in order to express being remembered for reading the quick botton of the setting value of customization by operator as shown in figure 14 It is loaded with " I, Gd, Bi (C) ".

Then, using Figure 15, the processing for the X ray CT device involved by the 1st embodiment is illustrated.Figure 15 is Flow chart for an example of the processing that illustrates the X ray CT device involved by the 1st embodiment.Wherein, in Figure 15 institutes In the flow chart shown, example goes out processing when setting value corresponding with quick botton has been stored in internal storage.

Like that, the control unit 38 of the X ray CT device involved by the 1st embodiment determines whether from behaviour example as shown in figure 15 Author has accepted specified (the step S101) of material.Here, when do not accept material it is specified when (step S101 negatives), control Portion 38 processed it is standby to accept to material specify untill.

On the other hand, when accept material it is specified when (step S101 affirmatives), control unit 38 judge the specified of material be No is accepting (step S102) based on quick botton.Specified when material is (step S102 when accepting based on quick botton Certainly), control unit 38 obtains the energy segmentation set (step S106) for setting and finishing according to characteristic energies value from internal storage.

On the other hand, when being not based on when accepting of quick botton (step S102 negatives), control unit 38 is to database 39 (step S103) is inquired about, answer (step S104) is determined whether it has received.Here, when not receiving answer (step S104 negatives), control unit 38 is standby untill answer is received.

On the other hand, when receiving answer (step S104 affirmatives), the setting of control unit 38 energy segmentation set (step S105).Wherein, when it is not characteristic energies value to answer, control unit 38 is judged as point of operator's material of interest not Analysis chemical data is registered in database 39, end processing.Or, control unit 38 can also be carried out to outside database again Inquiry.

Then, after step S105 or step S106, control unit 38 notifies energy segmentation set to collection portion 14 (step S107).Then, control unit 38 makes frame device 10 perform CT scan (step S108) via scan control section 33.And And, control unit 38 determines whether it has received the data set (step S109) for splitting the count results that set is collected into according to energy. Here, when not receiving data set (step S109 negatives), control unit 38 is standby untill data set is received.

On the other hand, when receiving data set (step S109 affirmatives), the control of control unit 38, image reconstruction portion are passed through 36 generation difference image datas (step S110), and generate overlapping image data (step S111).

Then, by the control of control unit 38, display device 32 shows overlapping image data (step S112), then terminates Processing.

As described above, in the 1st embodiment, appointing in the 1st setting method, the 2nd setting method and the 3rd setting method is passed through One method, according to the X-ray absorption characteristic of material, energetically sets optimal energy segmentation set.That is, in the 1st embodiment In, control unit 38 is set as multiple Energy identifying domains structure of the information needed for the image conversion that can ensure that operator's material of interest Into, and Energy identifying domain quantity tail off energy segmentation set.So as to which in the 1st embodiment, operator can be being ensured On the basis of data needed for the image conversion of material of interest, the data volume for carrying out image conversion is cut down.

In addition, in the 1st embodiment, the setting of energy segmentation set and the guarantor of setting value are carried out by handling in advance Pipe, and then show the quick botton that the setting value finished is obtained for reading.In addition, the setting value or quick botton being capable of bases The condition that operator is carried out changes to be updated or add.So as in the 1st embodiment, simplify of interest The operation of operator needed for the image conversion of material.

In addition, the setting method of the energy segmentation set involved by the 1st embodiment is not limited to above-mentioned setting method.Example Such as, it is contemplated that the characteristic energies value of the X-ray absorption characteristic of expression material such as K absorption limits is in actual measurement in a certain scope It is interior to swing.That is, the characteristic energies value obtained according to the information for being registered in database 39 is the reason by being preferably measured from Think value, the measured value obtained in actual measurement is sometimes different from ideal value.Thus, for example K absorbs the energy range before and after limit Domain turns into blind area, but in order to which the discriminating for effectively carrying out paying close attention to material is sometimes preferred.In consideration of it, being set when carrying out above-mentioned the 1st When method, the 2nd setting method and 3 setting method, the variation that control unit 18 can be illustrated below.

Because the material specified by operator is one, therefore, when carrying out 1 setting method, control unit 18 is except spy In region outside the front and rear region of performance value, setting energy segmentation set.For example, control unit 18 is by exemplified by Fig. 7 " in ER0~ER9 ", xenon K absorbs limit " E in Energy identifying domain_K=34.56keV " front and rear Energy identifying domain " ER5 " and " ER6 " is set as not collecting the blind area of count value.

Now, such as the 1st view data 101 is according to the count results of " C (ER4) " or the meter of " C (ER3), C (ER4) " Result or the count results of " C (ER0)~C (ER4) " etc. is counted to rebuild.In addition, for example the 2nd view data 102 is according to " C (ER7) count results or the count results of " C (ER7), C (ER8) " or the count results of " C (ER7)~C (ER9) " " Etc. rebuilding.In the variation of the 1st above-mentioned setting method, for example, the measured value of limit is absorbed in ideal value even in the K of xenon In the case that " 34.56keV " is nearby swung, the contrast agent of xenon class can be also emphasized to set the energy that can differentiate and splits collection Close.As a result, in above-mentioned variation, the difference image data 103 of the available contrast agent that can effectively identify xenon class.

Further, since the material specified by operator is multiple, therefore, when the 2nd setting method of progress or the 3rd setting method When, control unit 18 is set the plurality of in the region in addition to the region before and after the respective characteristic energies value of multiple materials The respective energy segmentation set of material.For example, when setting the segmentation set of the energy shown in Figure 10 and Figure 12,18 points of control unit Not by Th2 front and rear region " " Th2-d2 "~" Th2+d2# " ", Th3 front and rear region " " Th3-d3 "~" Th3+d3# " ", with And Th4 front and rear region " " Th4-d4 "~" Th4+d4# " " is set as blind area.Set in the variation of the 2nd setting method or the 3rd In the variation of method, even in each contrast agent K absorb limit measured value respectively ideal it is on weekly duty enclose swing in the case of, also can Enough emphasize each contrast agent and split set to set the energy that can differentiate.As a result, it is available to cut in above-mentioned variation The difference image data group of a variety of contrast agent is identified on the spot.

Wherein, value used in the setting of blind area can initially be set by control unit 18 in above-mentioned variation, also may be used To be manually set by operator.In addition, value can be manual by operator used in the setting of blind area in above-mentioned variation Change.In addition, be worth in above-mentioned variation used in the setting of blind area for example can according to the collecting amounts of data, absorb and limit The information such as measurement error, automatically changed by control unit 19.In addition, if carrying out above-mentioned variation for example can be by operating Person arbitrarily changes.

(the 2nd embodiment)

Collection portion 14 involved by 1st embodiment needs to split collection according to the energy that control unit 38 energetically changes setting Close to carry out Energy identifying.That is, collection portion 14 is needed to use changes according to the characteristic energies value for the material for turning into process object Multiple threshold values, dynamically to change and carry out Energy identifying.

In consideration of it, in the 2nd embodiment, gather for being split according to the energy set in the 1st embodiment, can The detector 13 of Energy identifying and the specific configuration example of collection portion 14 are performed, is carried out using Figure 16, Figure 17 and Figure 18 Explanation.Wherein, Figure 16 is the figure for the 1st configuration example for representing detector and collection portion shown in Fig. 1, and Figure 17 is to represent Fig. 1 institutes The detector and the figure of the 2nd configuration example of collection portion shown, Figure 18 is represent detector and collection portion shown in Fig. 1 the 2 The figure of configuration example.

In addition, in the following description, for set the I illustrated using Figure 10 with, Gd with and Bi three energy Amount segmentation set, collection portion 14 collect I shown in Figure 11 A with, Gd with and the Bi situation of energy aggregation illustrate.

First, for the 1st configuration example, illustrated using Figure 16." Amp " shown in Figure 16 is with constituting detector 13 Each detecting element 131 connect amplifier." Amp " shown in Figure 16 after the signal amplification for exporting each detecting element 131, Send to collection portion 14.As shown in figure 16, collection portion 14 has N number of comparator and the N number of counting being connected respectively with N number of comparator Device (counter 1, counter 2, counter 3 ..., counter (n-1), counter n).Given threshold is distinguished to N number of comparator (Th1、Th2、Th3、…、Th(n-1)、Thn).Control unit 38 can be to the arbitrary threshold value of each comparator change setting.

When having exceeded set threshold value from the Amp signals exported, each comparator shown in Figure 16 produces a pulse, The counter of back segment is counted to the number of the pulse produced by the comparator of leading portion.Here, due to collecting shown in Figure 11 A I with, Gd with and Bi energy aggregation, therefore, " Th1~Th5 " threshold values are set to 5 comparators.

In addition, in the back segment of N number of comparator, as shown in figure 16, a computing circuit is provided with, in the back segment of computing circuit It is provided with memory.On the memory shown in Figure 16, two memory blocks are set with as the region of storage I energy aggregations Domain (I (1) and I (2)).In addition, on the memory shown in Figure 16, being set with as the region of storage Gd energy aggregations Two storage regions (Gd (1) and Gd (2)).In addition, on the memory shown in Figure 16, being used as storage Bi energy aggregations Region and be set with two storage regions (Bi (1) regions and Bi (2)).

Computing circuit shown in Figure 16 is that basis is configured in the threshold value set in the comparator of the leading portion of each counter, will The counting that the count value for the counter being connected respectively with 5 comparators is exported to the multiple storage regions for being set in memory simultaneously The Port Multiplier of device.For example, computing circuit by the count value " C (ER1) " of Energy identifying domain " ER (1) " to I (1), Gd (1) and Bi (1) export.In addition, computing circuit by the count value " C (ER2) " of Energy identifying domain " ER (2) " to I (2), Gd (1) and Bi (1) Output.In addition, computing circuit is defeated to I (2), Gd (2) and Bi (1) by the count value " C (ER3) " of Energy identifying domain " ER (3) " Go out.In addition, computing circuit is defeated to I (2), Gd (2) and Bi (2) by the count value " C (ER4) " of Energy identifying domain " ER (4) " Go out.

Thus, as shown in figure 16, I (1) stores the count value of " C (ER1) ", I (2) storages " C (ER2)+C (ER3)+C (ER4)”.In addition, as shown in figure 16, the count value of Gd (1) storages " C (ER1)+C (ER2) ", Gd (2) storages " C (ER3)+C (ER4)”.In addition, as shown in figure 16, the count value of Bi (1) storages " C (ER1)+C (ER2)+C (ER3) ", Bi (2) storages " C (ER4)”。

Then, for the 2nd configuration example, illustrated using Figure 17." Amp " shown in Figure 17 is with constituting detector 13 All detecting elements 131 connect amplifier, " A/D " shown in Figure 17 be by " Amp " export amplification after simulation it is electric Signal is converted into the analog-digital converter of data signal." A/D " shown in Figure 17 sends data signal to collection portion 14.Such as Shown in Figure 17, collection portion 14 has computing circuit and memory.Computing circuit shown in Figure 17 be with comparator, counter, The circuit of the function of selector and Memory Controller.In addition, in the 2nd configuration example, also as shown in figure 17, in memory On as storage I energy aggregations region and be set with " I (1) and I (2) ", be used as storage Gd energy aggregations region And " Gd (1) and Gd (2) " is set with, it is set with 0 " Bi (1) regions and Bi as the region of storage Bi energy aggregations (2)”。

Computing circuit shown in Figure 17 is compared by comparator function to the output valve of " A/D ", meanwhile, pass through selection Device function, carries out the regional determination of each energy aggregation, by counter function, performs counting.Moreover, the computing electricity shown in Figure 17 Road for example by Memory Controller function, the count value of unit interval is write the region being consistent of memory.Thus, as schemed Shown in 17, the energy aggregation of each material is preserved in memory.Computing circuit shown in Figure 17 by control unit 38 according to being notified Setting value, used the processing of comparator function, selector function, counter function and Memory Controller function.

Then, for the 3rd configuration example, illustrated using Figure 18." Amp " shown in Figure 18 is with constituting detector 13 The amplifier that each detecting element 131 is connected, " A/D " shown in Figure 17 is the analog electrical signal after the amplification for exporting " Amp " Be converted to the analog-digital converter of data signal.In addition, the unit that the 1st memory shown in Figure 17 for example exports " A/D " The data signal of time quantum is taken care of as 10Bi t spike train.1st memory is, for example, repetition " write-in, replacement, exchange (swap) memory of double buffering construction ".

1st memory exports the spike train of unit interval to collection portion 14.As shown in figure 18, collection portion 14 has computing Circuit and the 2nd memory.Computing circuit shown in Figure 18 is with comparator, counter, selector and Memory Controller Function circuit.In addition, in the 2nd configuration example, also as shown in figure 18, storage I energy aggregations are used as on the 2nd memory Region and be set with " I (1) and I (2) ", as storage Gd energy aggregations region and be set with " Gd (1) and Gd (2) ", it is set with " Bi (1) regions and Bi (2) " as the region of storage Bi energy aggregations.

Computing circuit shown in Figure 18 is compared by comparator function to the spike train (data signal) of unit interval, Simultaneously by selector function, the regional determination of each energy aggregation is carried out, by counter function, counting is performed.Moreover, Figure 18 The count value of unit interval is for example write being consistent for the 2nd memory by shown computing circuit by Memory Controller function Region.Thus, as shown in figure 18, the energy aggregation of each material is preserved in the 2nd memory.Computing circuit root shown in Figure 18 According to the setting value notified from control unit 38, used comparator function, selector function, counter function and storage The processing of device controller function.

Wherein, the simulation which basis in the 1st configuration example of selection, the 2nd configuration example and the 3rd configuration example can be obtained The performance of digital quantizer, the circuit scale that can be equipped on frame device 10, Price Range of X ray CT device etc. are determined It is fixed.

In addition, the image procossing illustrated in above-mentioned embodiment can also be applied to be based on being given birth to by photon counting CT Into the intrinsic characteristic energies value of material view data it is overall.In addition, the image procossing illustrated in above-mentioned embodiment is such as Fruit can obtain count results, then can also be performed by the image processing apparatus set independently of X ray CT device.

In addition, the image processing method illustrated in the 1st and the 2nd embodiment can be by by personal computer or work The computer such as stand performs pre-prepd image processing program to realize.The image processing program can pass through the networks such as internet To issue.In addition, the image processing program is recorded in the embodied on computer readable such as hard disk, floppy disk (FD), CD-ROM, MO, DVD In recording medium, by the way that execution is read out from recording medium by computer.

As described above, according to the 1st and the 2nd embodiment, operator's material of interest can ensured Image conversion needed for data while, cut down the data volume for carrying out image conversion.

Although the description of several embodiments of the invention, but these embodiments are to point out as an example, not Intended limitation the scope of the present invention.These embodiments can be implemented in other various modes, not depart from invention master In the range of purport, various omissions, displacement, change can be carried out.The scope of these embodiments or its deformation with being contained in invention Or it is the same in purport, it is contained in the invention of claims record and its scope of equalization.

Claims (11)

1. a kind of X ray CT device, wherein, possess：

Collection portion, the photon to origin in the X-ray for having passed through subject is counted, by the energy of the photon counted The result differentiated is collected as count results；

Control unit, the energy for notifying to be set according to the X-ray absorption characteristic of the material specified by operator to above-mentioned collection portion Amount segmentation set；And

Image reconstruction portion, is received above-mentioned collection portion and is distinguished by gathering being split with above-mentioned energy multiple Energy identifying domains of setting Distribution counting value and the count results being collected into, and carry out reconstructed image data using the count results received,

Above-mentioned control unit is to the energy area of the vicinity of the characteristic energies value of the X-ray absorption characteristic of expression above-mentioned substance with tiny Granularity setting Energy identifying domain, Energy identifying domain is set with thick granularity to the energy area beyond the energy area, to set Fixed above-mentioned energy segmentation set.

2. X ray CT device according to claim 1, wherein,

Above-mentioned control unit sets above-mentioned energy segmentation collection in the region in addition to the region before and after above-mentioned characteristic energies value Close.

3. X ray CT device according to claim 1, wherein,

When specifying multiple materials by aforesaid operations person, above-mentioned control unit is according to the X-ray absorption characteristic for representing each material Characteristic energies value sets multiple Energy identifying domains, to set above-mentioned energy segmentation set.

4. X ray CT device according to claim 3, wherein,

Above-mentioned control unit binds in above-mentioned multiple Energy identifying domains slightly always according to above-mentioned multiple respective characteristic energies values of material Granularity multiple Energy identifying domains, thus set the segmentation set of above-mentioned multiple materials respective energy.

5. X ray CT device according to claim 4, wherein,

Above-mentioned control unit is in the region in addition to the region before and after above-mentioned multiple respective characteristic energies values of material, setting The plurality of respective energy segmentation set of material.

6. X ray CT device according to claim 1, wherein,

Above-mentioned control unit sets above-mentioned energy segmentation set before count results are collected.

7. X ray CT device according to claim 1, wherein,

The database that above-mentioned control unit is stored using pair information related to the respective X-ray absorption frequency spectrum of multiple materials, To set above-mentioned energy segmentation set.

8. X ray CT device according to claim 1, wherein,

Setting value used in the setting of above-mentioned energy segmentation set is set up and accordingly protected by above-mentioned control unit with the material being consistent In the presence of in defined storage part, display part will be shown in for the operation button for reading the setting value.

9. X ray CT device according to claim 1, wherein,

When the condition carried out according to aforesaid operations person changes above-mentioned energy segmentation set, above-mentioned control unit divides energy Setting value used in the reset that cut set is closed is set up with the material being consistent and is accordingly stored in defined storage part, will use Display part is shown in the operation button for reading the setting value.

10. a kind of image processing apparatus, wherein, possess：

Control unit, the energy point for notifying to be set according to the X-ray absorption characteristic for the material specified by operator for collection portion Cut set is closed, and photon of the collection portion to origin in the X-ray for having passed through subject count, and the light that will have been counted to this The result that the energy of son is differentiated is collected as count results；With

Image reconstruction portion, is received above-mentioned collection portion and is distinguished by gathering being split with above-mentioned energy multiple Energy identifying domains of setting Distribution counting value and the count results being collected into, and carry out reconstructed image data using the count results received,

Above-mentioned control unit is to the energy area of the vicinity of the characteristic energies value of the X-ray absorption characteristic of expression above-mentioned substance with tiny Granularity setting Energy identifying domain, Energy identifying domain is set with thick granularity to the energy area beyond the energy area, to set Fixed above-mentioned energy segmentation set.

11. a kind of image processing method is comprising following steps：

Control unit notifies the energy set according to the X-ray absorption characteristic for the material specified by operator is split to collect collection portion Close, photon of the collection portion to origin in the X-ray for having passed through subject is counted, and by the photon counted The result that energy is differentiated is collected as count results,

Image reconstruction portion is received above-mentioned collection portion and distinguished by gathering being split with above-mentioned energy multiple Energy identifying domains of setting Distribution counting value and the count results being collected into, and carry out reconstructed image data using the count results received,

Above-mentioned control unit is to the energy area of the vicinity of the characteristic energies value of the X-ray absorption characteristic of expression above-mentioned substance with tiny Granularity setting Energy identifying domain, Energy identifying domain is set with thick granularity to the energy area beyond the energy area, to set Fixed above-mentioned energy segmentation set.